Heavy metals phytoremediation using <i>Typha domingensis</i> Flourishing in an industrial effluent drainage in Kano, Nigeria

Abstract

Phytoremediation as a tool employs aquatic macrophytes as a principal and inexpensive strategy for controlling environmental pollution. It is achieved through various mechanisms such as phytoextraction, phytostabilization, and phytovolatilization. In this study, heavy metal content of a contaminated drainage that empties into the Kano River was investigated by assessing the uptake of heavy metal contaminants by a notorious aquatic weed, “Typha domingensis”. Atomic Absorption Spectrophotometer (AAS) was used to determine the concentration of Pb, Cu, Zn, Cr and Fe in the effluent, sediment and T. domingensis in the months of January, April and July 2013, covering the seasonal weather pattern in the area. In addition, the Bioconcentration factor (BCF) of these metal pollutants in T. domingensis, were calculated as the ratio of their concentration in Typha domingensis to the effluent while the Transfer factor (TF), as the ratio of these substances in T. domingensis to the sediment. From the results, Cu, Fe and Zn concentrations were statistically different (p<0.05) in the effluent as well as in the sediment across the sampling months, while Pb and Cr were significant only in the sediment. The BCF values obtained for these metals in the test plant were >1 except for Fe in April, which indicates the plant capacity for phytoextraction. Similarly, TF values obtained were >1 except for Pb, Fe and Cu in the months of January, April and July respectively. This also indicates the potentiality of T. domingensis as a nutrient and metalaccumulating plant through the process of sequestration. The findings of this work have demonstrated the capacity of T. domingensis in the effluent drainage, not only playing an ecological role in the environment, but also to remove heavy metal pollutants. Therefore, the plant species could be used for phytoremediation of industrial effluent contaminating ecosystems.

Keywords; T. domingensis, phytoremediation, Heavy metals, industrial effluent